The present invention relates to frequency synthesizers and more particularly to a frequency synthesizer employing acoustic devices, such as surface acoustic wave (SAW) or bulk acoustic devices.
Conventional frequency synthesizers employ filtering techniques based on mixers and dividers, phase locked loops or narrow filters to separate a single frequency line (discrete frequency) from a comb of frequencies derived from a single high quality reference oscillator. In order to get the necessary rejection and narrow bandpass characteristics desired, either very high quality filters must be employed, many successive stages of mixing and frequency division must be employed, or expensive programmable dividers must be employed in the phase locked loops.